This invention relates to a cable with a bending mechanism, and more particularly to a cable useful as an optical fiber sensor such as is used in a medical or industrial endoscope or to a laser beam surgical catheter.
In an optical fiber sensor such as is used in a medical or industrial endoscope, it is often required to externally operate the fiber sensor such that the fiber sensor is bent at its end portion to let an image pickup portion provided at the end portion face in a desired direction so as to pick up a desired image.
To meet this demand, an optical fiber sensor shown in FIG. 1 has been developed. As shown in FIG. 1, a plurality of knucle rings 6 are provided to encircle the fiber sensor body 8. The knucle rings 6 come into contact with one another at protruded support portions 7 provided in the center portions of the rings 6. Several operating wires 5 are provided at the peripheral portions of the knucle rings 6 in a symmetrical manner. According to such a structure of the optical fiber sensor, by tightening or pulling up one or many of the wires 5 but extending other one or many of the wires, the end portion of the fiber is bent to let the image pickup portion at the end portion thereof face in a desired direction.
However, the conventional optical fiber sensor having the above-described structure has such a problem that the fiber sensor as a whole is made thick by the use of the knucle rings 6. To the contrary, recently it has become possible to produce a very long but very thin image fiber which is used as a body of the optical fiber sensor.